Deep packet inspection (DPI), also referred to as “complete packet inspection and information extraction”, is a computer network packet analysis and inspection technique, and a device using the DPI technique (“DPI” device for short) may inspect a data portion (data) of a packet, and optionally may also inspect a header portion (header) of the packet, to acquire packet relevant information.
This acquired packet relevant information may be further used to perform deep packet analysis or network behavior analysis, such as: for determining whether there exists a situation of protocol nonuniformity, virus, junk mail, etc., and whether the packet involves network intrusion, etc.